Federal Circuit Distinguishes Between Enablement And Reasonable Expectation Of Success

In the recent UCB v. Accord opinion, a panel of the Federal Circuit drew a distinction between (i) the enablement of a patentee's claims, and (ii) a reasonable expectation of success in an obviousness analysis. The majority found that the presumption of enablement for a claimed genus of compounds did not preclude a finding that there was not a reasonable expectation of success in creating a species falling within that genus.

The patent in question (US RE38,551) recites in claim 1 the R-enantiomer of a compound having the formula:

wherein: Ar is phenyl which is unsubstituted or substituted with at least one halo group; Q is lower alkoxy; and Q1 is methyl.

A dependent pinpoint claim (8) recites the compound (R)-N-benzyl-2-acetamido-3-methoxypropionamide. This is the compound of claim 1 wherein Ar is unsubstituted phenyl, Q is methoxy, and Q1 is methyl. This compound is also known as lacosamide, an anti-epileptic drug marketed under the tradename Vimpat®.

As part of Abbreviated New Drug Applications (ANDAs), several generic drug manufacturers alleged that claims relating to lacosamide in the '551 patent were invalid. One of the grounds for invalidity was nonstatutory, obviousness-type double patenting.

The double-patenting theory relied on the claims of US 5,654,301. In particular, claim 39 of the '301 patent recites a compound having the formula:

wherein: R is aryl, aryl lower alkyl, heterocyclic, heterocyclic lower alkyl, cycloalkyl or lower cycloalkyl lower alkyl, wherein R is unsubstituted or is substituted with at least one electron withdrawing group or an electron donating group; R1 is hydrogen or lower alkyl and R1 is unsubstituted or substituted with at least one electron withdrawing group or at least one electron donating group; A and Q are both O; and one of R2 and R3 is hydrogen and the other is lower alkyl which is substituted with an electron donating group or an electron withdrawing group and n is 1-4.

In the district court bench trial, it was undisputed that lacosamide falls within the broad genus of claim 39 of the '301 patent (i.e., if R were unsubstituted benzyl, R1 were unsubstituted methyl, R2 were hydrogen, R3 were methoxymethyl, and n were 1). The generic drug manufacturers argued that lacosamide was merely an obvious species of the genus claimed in the '301 patent. Thus, they argued that the claims directed to lacosamide in the '551 patent were invalid on the ground of obviousness-type double patenting over the claims of...